Clock



Feb. 14, 1928e F. C. HOLTZ CLOCK Filed Nov. l5, 1924 Patented Feb. 14, 1928.

AUNITED STATES PATENT OFFICE.

FREDERICK C. HOLTZ, F SPRINGFIELD, ILLINOIS, ASSIG-NOR T0 SANGAMO ELECTRIC COMPANY, OF SPRINGFIELD, ILLINOIS, A CORPORATION 0F ILLINOIS.

CLOCK.

Applicationled November 15, 1924. Serial No. 750,201.

My invention relates to clocks, and lhas particularly to do with the driving mechanism by which the time train of Jhe clock is actuated. The primary object of my in vention is to provide-a clock or similar mechanism'fwith a low power electric. motor drive 'designed to obtain a maximum of simplicity in construction, whereby liability to derangement is reducedl to a minimum, and

of such character that while the highly developed construction of a modern clock movement is retained to a largeextent, it 1s rendered possible with but slight. alteration to drive the same electrically whereby it will require but little or no attention for long periods of time. A further object is to so design the mechanism that it will be compact; that a constant driving torque K will be exerted, thereby greatly improvin the time-keeping qualities ofthe clock, anl

that all electrical contact devices will be eliminated and the electrical energy consumption be reduced t0 a minimum. I accomplish these objects as illustrated in the drawings and as hereinafter described.

What I regard as new is set forth in the claims.

In the accompanying drawings,-

, Fig. 1 is a top or plan view of my improved clock, the case being omitted;

Fig. 2 is a side view, partlyv invertlcal section on line 2-2 of Fig. l;

Fig. 3 is a modie'd perspective view illustrating the relative arrangement of the clock movement and the driving mechanism therefor, some parts being omitted for the sake of clearness;

Fig. 4 is a side view of the rotor element of the motor by which the main spring of the clock is maintained under uniform tension, some parts being in section; and

Fig. 5 is an enlarged view ot the spring barrel, the shaft on which said barrel is mounted being shownin section.

Referring to the drawings,6 indicates generally a clock movement of any suitable description, and 7 the drive stati thereof, by the rotation of which the torque necessary to keep the balance stad or pendulum in a constant state ot oscillation is supplied. Said staff is connected with the time train of the clock in any suitable way and, as best shown in Fig. 3, carries at its outer end a pinion 8 through which said stad is driven, as will be hereinafter described. The clock movement 6 is mounted between pillar plates 9, 10, as shown in Fig. 2, and is provided with the usual balance wheel 11, or equivalent device, and with a regulator 12. EX- tending over the pillar plate 9 is a dial plate 13 over which move the usual hour and minute hands 14, 15.

For driving the time train .of the clock I provide a small induction motor, the stator of which comprises a single phase bipolar laminated field magnet, indicated as a whole by the reference numeral 16, on which is mounted a coilv 17 which constitutes the primary winding of the motor and is t0 be connected through its terminals 17, 17b to a source of supply of alternating current. Thel poles 18, 19 of the field magnet 16 .have their opposite faces curved so that a cylindrical opening is provided between them in which is rotatably mounted the armature or rotor 20 of the motor. Said rotor comprises a magnetic core member made up of a plurality of laminations 21, anda squirrel cage winding thereon consisting of bars 22 and end plates 23, 24, which plates serve as end-rings for the squirrel cage. The squirrel cageis preferably made of copper, and as best shown in Fig. 4

the bars 22 are obliquely disposed, the latter arrangement being employed to give uniform starting torque and thereby avoid a pulsating effect on the balance wheel spring. The ends of the bars 22 are preferably upset after the parts of the Vrotor are assembled, as illustrated `in Fig. 4, so that they serve to securely hold the laminations together. While I prefer to use a laminated rotor, it is not essential that it be laminated, as a solid structure for many purposes will function equally well.

The rotor is mounted on a suitable shaft 25 to rotate therewith, said shaft being provided with a worm'26, preferably cut di rectly on said shaft, and with pivot ins 27,- 28 at its opposite ends, by means o which it may be rotatably supported in the manner hereinafter described.

As best shown in Figs. 1 and 3, the field magnet poles 18, 19 are provided with shading coils 29, 30 mounted onthe pole-tips in the manner well known to those familiar with the art, which shading coils serve to change the pulsating flux of the field into a so-called shifting or substantially rotating magnetic leld inthe cylindrical space between the opposite poles of the lield magnet. As best shown in Figs. l and 3, the lield ma net 16 is mounted between two inverted tl-sllaped yolres 3l, 32, the intermediate portions of which are bent outwardly to accommodate the shading coils 29, 30. in the intermediate portion of the yoke 3l is mounted a bearing plug 33 fitter in a threaded opening so that it may be adjusted endtvise. Said plug is providedfat its inner end with a socket to receive the pivot pin 28 ofthe rotor shaft 25,*a-s best shown in Fig. 2. A lock nut 34 screwed upon the inner end of said bearing plug holds it securely in its different positions ot adjustment. [is shown in Fig. 2, the intermedia-te portion of the yoke 32 is provided with an opening 35 large enough to permit of the free passage. therethrough ot the armature shaft 25 and Worm 26, and the pivot pin 27 ot the rotor shaft 25 is fitted in a suitable bearing in a bearing plug 36 screwed into a threaded opening` in a U-shaped bracket `37 that is secured by screvvs 38 to the yolres 3l, 32 and lies between the field magnet and the pillar plate l0. By this construction the rotor shaft 25 is securely mounted and'held so that it cannot get out of place, and the rotor is held in proper relation to the poles of the field magnet. "A lock nut 36 is screwed on the inner end ot the bearing plug 36 to secure it in its di'erent positions ot adjustment. `At opposite sides of one end of the bracket 37 are provided Wings 39, 40, the Wing 39 being best shown in Fig. l and the Wing 4:0 in Fig. 2. rlhese Wingsv are bent over approximately at right angles to the part ot the bracket 3 with which they are connected and are parallel with each other. Their purpose is to support a shatt- 41, best shown in Fig. 3, and to this end they are provided With suitable bearings in which said shaft is mounted. As shown in Fig. 3, the lower end ot the shaft 4l is fitted in a bearing in the wing Ll0, and' as indicated by dotted lines in Fig. l the op posite end ot said shaft extends through a suitable bearing in the wing 39. Aabove said Wing the shaft 1li. is provided with a Worin Wheel 42 that meshes with and is driven by the worin 26 on the rotor shaft as shown in Figs. l and 3. The shaftsl also carries a worm Li3 that meshes with and drives i, Worm Wheel 44 carried by a drive shaft 45 mounted at one end in a suitable bearing in an arm 46 carried by the intermediate portion of the bracket 37, and at the other end journaled in a. bearing' in a plate l? secured to the intermediate portion ot the yoke 32. preferably by rivets 43. The arm i6 and plate 47 hold the shaft l5 securely in place, and as they constitute. a part of rigid trarne which includes the yolzes 3l, 32, which in turn are firmly secured to the field magnet, it will he seen that the field magnet, with` the driving' connections supported resaca? such trame, may be handled as a unit. This frame is firmly secured to the pillar plate l0 by a bracket 49 Which is attached to said pillar plate in any suitable Way, and is provided with a lugv 50 adapted to fit over one of the out-turned ends 51`ot' the brackets 3T so that it may be secured thereto and to the tield magnet by one of the screws 38, as best .shown in Fig. l.

At its inner end lthe shatt- 45 has loosely mounted upon it a spring barrel 52 adapted to receive a main spring 53, the outer end ot which is secured to said barrel, as shown at 54 in Fig. 5. rlhe inner convolution of said spring is secured to the shaft 45 in any suitable Way, as' shown at 55 in Fig. 5. The arrangement is such that when the motor is in operation the shaft 45 Will be rotated in a counter-clockwise direction as viewed in Fig. 5, thereby Winding' up the spring 53, assuming that the spring barrel 52 is held so that it cannot rotate in the same direction with the shaft 45., The spring barrel 52 is provided at its periphery with a gear 56 that meshes with the pinion 8, as shown in Fig. 3, the arrangement being such that rotation ot' the spring barrel under the action ot the main spring 53 will rotate the pinion 8 inV the proper direction to drive the time train. From the foregoing description it will be apparent that the main spring 53 may be Wound up by the operation ot the motor, and that speed reducing gearing is provided between the rotor shaft of the motorrand the shaft 45 by which the spring is wound. llhe object ot' thisjspeed reducing gearing is to accommodate the speed of unwind ot' the spring barrel 52 to the speed of the induction motor, Whose Winding 17 is connected t0 any suitable source of alternating current supply, so that the motor will keep 'the spring 53 Wound to a certain fixed tension, thus providing a constant torque in driving the clock mechanism. Any slight variation in the speed et the motor merely. increases-or decreases slightly the tension ot the spring. Should'the motor stop entirely, the barrel 52 continues to rotate until the spring 53 is unwound, as will occur should the electric power supply for any reason be disconnected. lt is intended that the reserve power in the spring shall be suliicient to keep the clock running tor several hours Without the aid or the motor, and this, in most instances, will bridge over any discon tinuities in the electric power supply, thus enabling` the clocl to run almost indelinitely after being connected to a source of supply.

nilhile l' have described my invention as operated from a small alternating current motor, it "will be quit-e evident to those skilled the that a small direct current motor similar principles would operating under .tall Within the scope my invention.

Leases? 'on said motor shaft, a worm on said second shaft, a third shaft extending substantially parallel to said motor shaft and journaled at one end in said bracket, and a worin wheel on said third-shaft meshing with the worm on said second shaft, said third shaft being adapted to transmit a drive to the clock.

2. In a winding device for spring motors, the combination of an electric motor having an extending motor shaft, a U-shaped bracket secured to said motor and having a 'bea-ring at its outer end for receiving the 25 extending end of said inotor shaft, a' worm on said motor shaft, two spaced wings projecting inwardly -i from one side ofsaidy bracket, -a vsecond shaft jonrnaled in said wings, a worm' wheel on said second shaft meshing with lthe worm on said motor shaft,

a worm onsaid second shaft, a third shaft extending at an angle to said second shaft, bearing means for said third shaft carried by said bracket, and a worm wheel onsaid third shaft meshing with the worm on said second shaft, said third shaft being adapted to transmit a slow speed winding rotation to the spring motor.

3. In an electric driving device for clocks, the `combination of an electric motor having an extending motor shaft, a yoke secured to said motor, aU-shaped bracket extending outwardly from one side of said motor and having a bearing at its end for receiving the extending end of said motor shaft, a worm on said motor. shaft, two spaced wings projecting inwardly from one side of said bracket, a Second shaft journaled in said Wings, a worm wheel on said second shaft meshing-with the worin on said motor shaft,

a' worm on said second shaft, an arm car-l ried by said yoker and vhaving a bearing therein alined with a bearing in said bracket.,

a third shaft journaled in said bearings, and a worin wheel on said third shaft meshing i with the worm on said second shaft, said third shaft being adapted to 'transmit a slow speed drive to the clock.

4. In a winding device for spring motors, the combination of an alternating current induction motor comprising a laterally extending rotor shaft, a yoke at one side of said motor, a U-shaped bracket secured to said motor and extending from the other side thereof, bearing plugs screwing into threaded openings in said yoke and said bracket and receiving the ends of said rotor shaft, a worin on said rotor shaft, a pair of wings bent inwardly from one of the side arm portions of said bracket, a second shaft journaled in said wings, a worm wheel on said second shaft meshing with the worin on said rotor shaft, a worm on said second shaft, a bearing arm carried by the outer end of said bracket, a cooperating bearing plate carried by said motor, a third shaft journaled in said bearing arm-'and bearing plate, and a worin wheel onsaid third shaft meshing with the worm on said second shaft, said third shaft being adapted for operative connection with the spring motor.

5. The combination with clock mechanism comprising pillar plates, a time train mounted between said pillar plates, a drive staff connected therewith, and a main spring having` a driving connection with said drive stafhof an electrically operated winding dcvice for said main spring comprising an induction motor, a frame member secured to one of said pillar plates and support.- ing said induction motor directly in rear of said pillar plates, said induction motor coniprising a rotor shaft extending forwardly towards said clock mechanism, a bearingr bracket extending from said motor toward said clock mechanism and affording a bearing support for the end of said rotor shaft, a worm on said rotor shaft, a second shaft extending at an angle to said rotor shaft, hearing means for said second shaft carried by said bearing bracket, a worm wheel on said second shaft meshing with the worin on said rotor shaft, a worm on said second shaft, a third shaft extending substantially parallel to said rotor shaft and jonrnaled in said bearing bracket, and a worin wheel on said third shaft meshing with the worin on said second shaft, said third shaft heilig adapted to transmit a slow speed winding rotation to said main spring. 

